File sharing with only one computer on the LAN

Help for v2
1

I’ve been reading through the tutorials, have not found my specific need. I want to file share with only one computer on the LAN, and block the rest. Can anyone direct me to a tutorial that covers what I need to do?

Thanks

2

Here’s the tutorial that I used to confing CPF
https://forums.comodo.com/index.php/topic,5340.0.html

3

I’d already seen that tutorial, but it creates more questions for me than it answers. But if that is all that is available, maybe someone can answer my questions.

Here are the rules it shows:

Rule #0
Action = Allow
Protocol = IP
Direction = Out
Source IP = pc1
Destination IP = router
IP details = Any

Rule #1
Action = Allow
Protocol = IP
Direction = In
Source IP = router
Destination IP = pc1
IP details = Any

Rule #3
Action = Allow
Protocol = IP
Direction = Out
Source IP = pc1
Destination IP = pc2
IP details = Any

Rule #4
Action = Allow
Protocol = IP
Direction = In
Source IP = pc2
Destination IP = pc1
IP details = Any

Rule #5
Action = Allow
Protocol = IP
Direction = Out
Source IP = pc1
Destination IP = pc3
IP details = Any

Rule #6
Action = Allow
Protocol = IP
Direction = In
Source IP = pc3
Destination IP = pc1
IP details = Any

Rule #7 (serves for finding the other 2 pcs by searching their name)
Action = Allow
Protocol = UDP
Direction = In
Source IP = broadcast adress of the router
Destination IP = pc1
Source Port = Any
Destination Port = Any
ps. For finding the brodcast adress of the router you can use:

  1. A simple subnet calculator like this one http://net.apollo.lv/subnet.php
  2. or with Advanced Subnet Calculator a free program a little more difficult to understand. http://www.softpedia.com/get/Network-Tools/Misc-Networking-Tools/Advanced-Subnet-Calculator.shtml

My questions:

  1. Why is there no rule #2? Is that just a typo?

  2. In rule 7 it refers to the “broadcast address of the router”. Is this different than the “router” IP referred to in rules 0 & 1? If so, what are the two IP’s it refers to?

  3. At the end it mentions 2 tools to get the router address. Would using ipconfig /all to get the gateway IP work for this?

  4. In my present configuration (have not done the above custom rules yet), I have 8 network rules, I guess they were created by the wizard, but I am not sure. Can I just remove all 8 of those rules, or are some needed for something else?

Thanks for the help

4

The easiest way to do this is to set up rules for ports 137 and 138 between the two IPs. If you use IN/OUT as a direction and a port range, you only really need one rule.

Rule for PC1

Action : ALLOW
Direction : IN/OUT
Protocol : TCP/UDP
Source IP : PC1
Destination IP : PC2
Souce ports : A range of ports (137-138)
Destination ports : A range of ports (137-138)

Rule for PC1

Action : ALLOW
Direction : IN/OUT
Protocol : TCP/UDP
Source IP : PC1
Destination IP : PC2
Souce ports : A range of ports (137-138)
Destination ports : A range of ports (137-138)

Rule for PC2

Action : ALLOW
Direction : IN/OUT
Protocol : TCP/UDP
Source IP : PC2
Destination IP : PC1
Souce ports : A range of ports (137-138)
Destination ports : A range of ports (137-138)

If you want full comms between the two PCs, use ANY instead of A RANGE OF PORTS in both rules.

Cheers,
Ewen :slight_smile:

5

That seems much easier, thanks.

2 questions now:
Do I need to run the network wizard at all, or do these rules do all I will need?

Do I need any rules to allow communication to/from the router, like the tutorial showed?

Thanks

6

Running the wizard will set up rules for ALL PCs on your LAN, not just a specific one, which would seem to be at odds to your origianl question.

Cheers,
Ewen :slight_smile: